Gear train and apparatus



NQV. 25, 1969 R. WOODY GEAR TRAIN AND APPARATUS 2 Sheets-Sheet 1 Filed Jan. 10, 1968 INVENTOR. Robe/v Woody BY NW. 25, 1969 R. woos! 3,479,896

GEAR TRAIN AND APPARATUS Filed Jan. 10, 1968 2 Sheets-$heot 2 lLJfl A 5 .58

11" l/LI HIIHIJ I Q 5; H1. :5 $4 1' mum I United States Patent 3,479,896 GEAR TRAIN AND APPARATUS Robert Woody, Bay City, Mich., assignor to The Dow Chemical Company, Midland,Mich., a corporation of Delaware Filed Jan. 10, 1968, Ser. No. 696,799 Int. Cl. F1611 55/04, 3/38 US. Cl. 74399 9 Claims ABSTRACT OF THE DISCLOSURE Two shafts adjustably positioned and generally parallel to each other are driven by a gear having an external and internal driving face of like pitch diameter. One shaft is supported on a support rotating about the axis of the driving gear.

This invention relates to a gear train, and more particularly. relates to an apparatus employing such a gear train to drive parallel adjustably spaced rolls.

Oftentimes, it is desirable to employ a pair of counterrotating rolls which are adjustably spaced for shaping, forwarding or processing operations. Oftentimes, it is desirable to have such rolls mounted in such a manner that synchronization is maintained between opposed rolls and spacing between the rolls is readily variable. Many drive systems have been devised for driving rolls in adjustable relationship. However, many of such drive mechanisms require many parts and pieces and achieve synchronization only with difiiculty. Some such drive mechanisms require constant speed universal joints in order to main tain synchronization and bearings to support the rolls which are slidably secured to a fixed frame. Frequently, it is desirable to employ rolls for processing operations such as fracturing or severing of strands wherein it is desired to maintain the rolls in spaced relationship and maintain the synchronization between rolls and provide an assembly that will increase the spacing between the rolls if an unexpected quantity of material is fed thereto. Oftentimes, it is desired that such rolls grip a material being fed therebetween in that the amount of force exerted on the material increases with increased resistance of the supply source of such a material.

It would be desirable if there were available an improved drive means for spaced apart parallel shafts.

It would also be desirable if there were available an improved drive means for spaced apart parallel shafts which would permit ready adjustment of the spacing between such parallel shafts.

It would also be desirable if there were available a mechanism which would permit close control of synchronization between spaced apart parallel shafts.

These benefits and other advantages in accordance with the present invention are achieved in an apparatus in accordance with the invention which comprises a support means, the support means having rotatably journaled therein a first rotating shaft having an axis, a second shaft in generally parallel relationship to the first shaft, a first shaft gear means affixed to the first shaft, a second shaft gear means affixed to the second shaft, the first shaft gear means having an internal driving face having a pitch diameter of A in operative engagement with the second gear means which has a pitch diameter less than A, the first gear means having external driving face having a pitch diameter of A, the support means having rotatably journaled therein a third shaft, the third shaft having a third gear means in operative engagement with the external driving face and the second shaft and the third shaft capable of relative rotation about the first shaft.

3,479,896 Patented Nov. 25, 1969 Further features and advantages of the present invention will become more apparent from the following specification taken in connection with the drawing wherein:

FIGURE 1 is a schematic representation of the operation of one embodiment of the invention.

FIGURES 2 and 3 are views of an apparatus in accordance with the invention.

FIGURE 4 is a sectional View of the apparatus of FIGURE 3 taken along the line 4-4.

In FIGURE 1 there is schematically depicted the operation of one embodiment of the invention generally designated by the reference numeral 10. A first shaft 11 is rotatably supported by a means not shown. A second shaft 12 is rotatably supported parallel to the first shaft 11. A first gear means 14 is afiixed to the first shaft 11. The first gear means 14 has an internal driving face 15 and an external driving face 16. The driving faces 15 and 16 are of equal pitch diameter. The second shaft 12 has afiixed thereto a second gear means 17 which is in operative communication with the first or internal driving face 15. A bearing support or arm 18 is pivotally supported by the first shaft 11. The arm 18 rotatably supports a third shaft 19 parallel to the first and Second shafts 11 and 12 and permits relative rotation of the shafts 12 and 19 about the shaft 11. A third gear means 21 is afiixed to the shaft 19 and is in operative communication with the second or external driving face 16. An elongate article 22 passes between the shafts 12 and 19 and is operated upon by rolls or other rotary means not shown carried on the shafts 12 and 19. An arm positioning means 23 operates on the arm 18 to selectively position it about the axis of the first shaft 11.

The gear train depicted in FIGURE 1 is driven in the direction indicated by the arrows by applying a driving force to the second shaft 12 provides an arrangement which permits a material 22 to be fed between operating rolls carried on the shafts 12 and 19 wherein if the dimension of the material 22 is increased suddenly, the arm 18 pivots and moves the shaft 19 away from the shaft 12 permitting the material to pass without jamming assuming that the positioning means 23 ofiers some predetermined resistance to motion over the desired are; that is, the positioning means 23 is a spring, pneumatic cylinder or the like. If constant driving force is applied to the shaft 11, the material 22 will be positively forwarded, and if an increased force is required to forward the material 22, the arm 18 will tend to pivot in the direction of the arrow by the reference numeral 23 causing the rolls or operating means to exert an increased clamping force on the material being forwarded therethrough. Alternately, the material 22 may be drawn or pushed between operating rolls supported on the shafts 12 and 21 imparting driving force to both the shafts 12 and 21 while the gear means 14 causes them to remain in synchronization. Such an arrangement is frequently desirable in embossing applications.

One application of the principle of the invention is depicted in the apparatus of FIGURES 2, 3 and 4. In FIGURES 2 and 3 there is depicted an apparatus generally designated by the reference numeral 25. The apparatus 25 comprises in cooperative combination a frame or support 26. The support 26 has opposed bearing supports 28 and 29 defining a space 30 therebetween. The bearing supports 28 and 29 carry a pair of opposed spaced apart bearings 31 and 32, respectively. A first shaft 33 is rotatably supported by the bearings 31 and 32. The supports 28 and 29 carry bearings 35 and 36 which are in spaced relationship to the bearings 31 and 32. A second shaft 38 is rotatably supported by the bearings 35 and 36 and is in spaced parallel relationship to the shaft 33. Bearing support arms 39 and 40 are pivotally afiixed to the shaft 33 and positioned external to the supports 28 and 29. The

3 arms 39 and 40 rotate about the center of the shaft 33. The bearing support arms 39 and 40 carry bearings 42 and 43, respectively, which rotatably support a third shaft 44 which is in spaced parallel relationship to the first and second shafts 33 and 38. An arm positioning means 46 is operatively connected to a link 47 extending between the arms 39 and 40. The link 47 maintains the arms 39 and 40 in parallel relationship. A first gear means 48 is afiixed to the first shaft 33. The first gear means 48 has an external driving face 50 and an internal driving face 51. The driving faces 50 and 51 are of like pitch diameter. The second shaft 38 has affixed thereto a second gear means 53 in operative engagement with the internal driving face 51 of the first gear means 48. A third gear means 54 is supported on the third shaft 44 and is in operative engagement with the external driving face 50 of the first gear means 48. A first toothed drum 56 is supported and rotated by the second shaft 38. A second toothed drum or roll 57 is carried and affixed to the shaft 44. The first drum 56 has a plurality of spaced apart parallel teeth 58 and the second drum 57 has a plurality of spaced apart teeth 59. The drums 56 and 57 are of like diameter and have like spacing between the teeth. A drive pulley 61 is affixed to the second shaft 38 and is in operative communication with a motor 62 by means of a belt 63.

FIGURE 4 is a sectional view of the apparatus of FIG- URES 2 and 3 taken along the line 44 of FIGURE 3 which illustrates the arrangement of the first, second and third gear means.

The apparatus of FIGURE 3 is useful for a variety of processes, including embossing, forwarding and the like and is employed with particular advantage for the formation of pellets from a plurality of brittle strands passed between the drums 56 and 57 wherein the teeth of opposing drums are adapted to sever the strands by pinching if the teeth are arranged to synchronize in a point to point manner, or snap the strands if the teeth are disposed in such a manner that they tend to interdigitate when they approach each other.

The operation of the embodiment of FIGURES 2, 3 and 4 is substantially that schematically depicted in FIG- URE 1. Beneficially, the positioning means 46 resiliently tensions the arm 39 in a desired position to maintain the rolls 56 and 57 in such a manner that they do not contact each other. Apparatus such as the apparatus of FIGURES 2, 3 and 4 may readily be constructed from readily available components if the first gear means is assembled from an internal ring gear and a spur gear having like pitch and pitch diameter wherein the ring gear is engaged with the spur gear and the faces of the gears are offset and held in position by means of set screws. Alternately, the internal ring gear may be mounted on the opposite end of the shaft 33 and the second gear 51 also positioned on the opposite end of the shaft 38. Generally where precise synchronization is required, anti-backlash gears are preferred.

As is apparent from the foregoing specification, the present invention is susceptible of being embodied with various alterations and modifications which may differ particularly from those that have been described in the preceding specification and description. For this reason, it is to be fully understood that all of the foregoing is intended to be merely illustrative and is not to be construed or interpreted as being restrictive or otherwise limiting of the present invention, excepting as it is set forth and defined in the hereto-appended claims.

What is claimed is:

1. An apparatus comprising 4 a support means, the support means havingrotatably journaled therein V i a first rotating shaft having an axis, a second shaft in generally parallel relationship to the first shaft, a first shaft gear means affixed to the first shaft, a second shaft gear means afiixed to the second shaft, the first shaft gear means having an internal driving face having a pitch diameter of A in operative engagement with the second gear means which has a pitch diameter less than A, the first gear means having an external driving face having a pitch diameter of A, the support means having rotatably journaled therein a third shaft, the third shaft having a third gear means in operative engagement with the external driving face, and the second shaft and the third shaft being capable of relative rotation about the axle of the first shaft.

2. The apparatus of claim 1 wherein the second shaft and third shaft each have a work engaging-roll disposed thereon and afiixed thereto.

3. The apparatus of claim 2 wherein the work engaging drums are toothed drums.

4. The apparatus of claim 3 including means to position the second shaft relative to the first shaft.

5. The apparatus of claim 4 wherein the positioning means resiliently tensions the third shaftin a desired location.

6. The apparatus of claim 1 wherein the support means comprises a support and a third arm support pivotally carried on the first shaft.

7. The apparatus of claim 1 in operative combination with means to rotate at least one of said shafts.

8. The apparatus of claim 7 wherein the means to rotate is connected to the second shaft.

9. An apparatus comprising a support means, the support means having rotatably supported thereon (a) a first gear means having an axis, (b) a second gear means having an axis, the first gear means having an internal driving face having a pitch diameter of A in operative engagement with the second gear means which has a pitch diameter less than A, the first gear means having an external driving face having a pitch diameter of A, the support means having rototably supported thereon (c) a third gear means in operative engagement with the external driving face, the second gear means and the third gear means being capable of relative rotation about the axis of the first gear means.

References Cited UNITED STATES PATENTS 2,813,434 11/1957 Stuebs 74384X 3,166,948 1/1965 Crowe 74-397 LEONARD H. GERIN, Primary Examiner US. Cl. X.R. 74-438 

